What would you do when you hack into your girlfriend’s social account and found out she had been exchanging naked pictures with a secret lover?

I (Name withheld) had been suspecting my girlfriend may have been cheating on me. I started  noticing changes in her behavior. She stops listening; she was always on a long calls whenever I try pulling a call through her. She gives excuses why she can’t be at my place at a certain time as she used to.  She always had new make ups, new clothes, new shoes, new everything. She smiles differently. And whenever she finally comes to my place, her text messages and call history are always wiped clean. She now uses password on her phone; she regularly changes the passwords whenever I ask for the previous one

This give me no doubt than to conclude she is seeing some else, something she always denies. 

I used to have access to her social accounts, and I was shocked that the passwords had been changed too. This new reality disturbs me greatly. So, an idea came up in my head “hack her social account” it will be a good start finding out the truth.

My girlfriend was a dummy; she hides things in the simplest place to find it. So I knew her passwords would be the simplest keys words something that has to do with her. So I made list of everything around and about her, and bingo, I found one that works. I finally hacked into her social account, and  I was shocked as to what I found. What should I do?